This patch add support for page access protection bits. Till now this
feature was disabled and Exynos SYSMMU always mapped pages as read/write.
Now page access bits are set according to the protection bits provided
in iommu_map(), so Exynos SYSMMU is able to detect incorrect access to
mapped pages. Exynos SYSMMU earlier than v5 doesn't support write-only
mappings, so pages with such protection bits are mapped as read/write.
Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
---
drivers/iommu/exynos-iommu.c | 63 +++++++++++++++++++++++++++++++++++---------
1 file changed, 51 insertions(+), 12 deletions(-)
diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
index 30808e9..e249e2f 100644
--- a/drivers/iommu/exynos-iommu.c
+++ b/drivers/iommu/exynos-iommu.c
@@ -70,6 +70,36 @@
#define SYSMMU_PG_ENT_SHIFT 0
#define SYSMMU_V5_PG_ENT_SHIFT 4
+static const sysmmu_pte_t *LV1_PROT;
+static const sysmmu_pte_t SYSMMU_LV1_PROT[] = {
+ ((0 << 15) | (0 << 10)), /* no access */
+ ((1 << 15) | (1 << 10)), /* IOMMU_READ only */
+ ((0 << 15) | (1 << 10)), /* IOMMU_WRITE not supported, use read/write */
+ ((0 << 15) | (1 << 10)), /* IOMMU_READ | IOMMU_WRITE */
+};
+static const sysmmu_pte_t SYSMMU_V5_LV1_PROT[] = {
+ (0 << 4), /* no access */
+ (1 << 4), /* IOMMU_READ only */
+ (2 << 4), /* IOMMU_WRITE only */
+ (3 << 4), /* IOMMU_READ | IOMMU_WRITE */
+};
+
+static const sysmmu_pte_t *LV2_PROT;
+static const sysmmu_pte_t SYSMMU_LV2_PROT[] = {
+ ((0 << 9) | (0 << 4)), /* no access */
+ ((1 << 9) | (1 << 4)), /* IOMMU_READ only */
+ ((0 << 9) | (1 << 4)), /* IOMMU_WRITE not supported, use read/write */
+ ((0 << 9) | (1 << 4)), /* IOMMU_READ | IOMMU_WRITE */
+};
+static const sysmmu_pte_t SYSMMU_V5_LV2_PROT[] = {
+ (0 << 2), /* no access */
+ (1 << 2), /* IOMMU_READ only */
+ (2 << 2), /* IOMMU_WRITE only */
+ (3 << 2), /* IOMMU_READ | IOMMU_WRITE */
+};
+
+#define SYSMMU_SUPPORTED_PROT_BITS (IOMMU_READ | IOMMU_WRITE)
+
#define sect_to_phys(ent) (((phys_addr_t) ent) << PG_ENT_SHIFT)
#define section_phys(sent) (sect_to_phys(*(sent)) & SECT_MASK)
#define section_offs(iova) (iova & (SECT_SIZE - 1))
@@ -97,16 +127,17 @@ static u32 lv2ent_offset(sysmmu_iova_t iova)
#define SPAGES_PER_LPAGE (LPAGE_SIZE / SPAGE_SIZE)
#define lv2table_base(sent) (sect_to_phys(*(sent) & 0xFFFFFFC0))
-#define mk_lv1ent_sect(pa) ((pa >> PG_ENT_SHIFT) | 2)
+#define mk_lv1ent_sect(pa, prot) ((pa >> PG_ENT_SHIFT) | LV1_PROT[prot] | 2)
#define mk_lv1ent_page(pa) ((pa >> PG_ENT_SHIFT) | 1)
-#define mk_lv2ent_lpage(pa) ((pa >> PG_ENT_SHIFT) | 1)
-#define mk_lv2ent_spage(pa) ((pa >> PG_ENT_SHIFT) | 2)
+#define mk_lv2ent_lpage(pa, prot) ((pa >> PG_ENT_SHIFT) | LV2_PROT[prot] | 1)
+#define mk_lv2ent_spage(pa, prot) ((pa >> PG_ENT_SHIFT) | LV2_PROT[prot] | 2)
#define CTRL_ENABLE 0x5
#define CTRL_BLOCK 0x7
#define CTRL_DISABLE 0x0
#define CFG_LRU 0x1
+#define CFG_EAP (1 << 2)
#define CFG_QOS(n) ((n & 0xF) << 7)
#define CFG_ACGEN (1 << 24) /* System MMU 3.3 only */
#define CFG_SYSSEL (1 << 22) /* System MMU 3.2 only */
@@ -481,6 +512,8 @@ static void __sysmmu_init_config(struct sysmmu_drvdata *data)
else
cfg = CFG_QOS(15) | CFG_FLPDCACHE | CFG_ACGEN;
+ cfg |= CFG_EAP; /* enable access protection bits check */
+
writel(cfg, data->sfrbase + REG_MMU_CFG);
}
@@ -652,10 +685,15 @@ static int __init exynos_sysmmu_probe(struct platform_device *pdev)
__sysmmu_get_version(data);
if (PG_ENT_SHIFT < 0) {
- if (MMU_MAJ_VER(data->version) < 5)
+ if (MMU_MAJ_VER(data->version) < 5) {
PG_ENT_SHIFT = SYSMMU_PG_ENT_SHIFT;
- else
+ LV1_PROT = SYSMMU_LV1_PROT;
+ LV2_PROT = SYSMMU_LV2_PROT;
+ } else {
PG_ENT_SHIFT = SYSMMU_V5_PG_ENT_SHIFT;
+ LV1_PROT = SYSMMU_V5_LV1_PROT;
+ LV2_PROT = SYSMMU_V5_LV2_PROT;
+ }
}
pm_runtime_enable(dev);
@@ -954,7 +992,7 @@ static sysmmu_pte_t *alloc_lv2entry(struct exynos_iommu_domain *domain,
static int lv1set_section(struct exynos_iommu_domain *domain,
sysmmu_pte_t *sent, sysmmu_iova_t iova,
- phys_addr_t paddr, short *pgcnt)
+ phys_addr_t paddr, int prot, short *pgcnt)
{
if (lv1ent_section(sent)) {
WARN(1, "Trying mapping on 1MiB@%#08x that is mapped",
@@ -973,7 +1011,7 @@ static int lv1set_section(struct exynos_iommu_domain *domain,
*pgcnt = 0;
}
- update_pte(sent, mk_lv1ent_sect(paddr));
+ update_pte(sent, mk_lv1ent_sect(paddr, prot));
spin_lock(&domain->lock);
if (lv1ent_page_zero(sent)) {
@@ -991,13 +1029,13 @@ static int lv1set_section(struct exynos_iommu_domain *domain,
}
static int lv2set_page(sysmmu_pte_t *pent, phys_addr_t paddr, size_t size,
- short *pgcnt)
+ int prot, short *pgcnt)
{
if (size == SPAGE_SIZE) {
if (WARN_ON(!lv2ent_fault(pent)))
return -EADDRINUSE;
- update_pte(pent, mk_lv2ent_spage(paddr));
+ update_pte(pent, mk_lv2ent_spage(paddr, prot));
*pgcnt -= 1;
} else { /* size == LPAGE_SIZE */
int i;
@@ -1013,7 +1051,7 @@ static int lv2set_page(sysmmu_pte_t *pent, phys_addr_t paddr, size_t size,
return -EADDRINUSE;
}
- *pent = mk_lv2ent_lpage(paddr);
+ *pent = mk_lv2ent_lpage(paddr, prot);
}
dma_sync_single_for_device(dma_dev, pent_base,
sizeof(*pent) * SPAGES_PER_LPAGE,
@@ -1061,13 +1099,14 @@ static int exynos_iommu_map(struct iommu_domain *iommu_domain,
int ret = -ENOMEM;
BUG_ON(domain->pgtable == NULL);
+ prot &= SYSMMU_SUPPORTED_PROT_BITS;
spin_lock_irqsave(&domain->pgtablelock, flags);
entry = section_entry(domain->pgtable, iova);
if (size == SECT_SIZE) {
- ret = lv1set_section(domain, entry, iova, paddr,
+ ret = lv1set_section(domain, entry, iova, paddr, prot,
&domain->lv2entcnt[lv1ent_offset(iova)]);
} else {
sysmmu_pte_t *pent;
@@ -1078,7 +1117,7 @@ static int exynos_iommu_map(struct iommu_domain *iommu_domain,
if (IS_ERR(pent))
ret = PTR_ERR(pent);
else
- ret = lv2set_page(pent, paddr, size,
+ ret = lv2set_page(pent, paddr, size, prot,
&domain->lv2entcnt[lv1ent_offset(iova)]);
}
--
1.9.1
--
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